Abstract

In order to investigate a new clean and chromium-free tanning method, an epoxy-modified starch (SCT) tanning agent was prepared from natural corn starch degradation products and we have examined its combined tanning effect with aluminum salts. The results showed that when the offer of SCT tanning agent was 8% of the mass of pickled sheep, and the offer of aluminum salt was 6%, at a tanning pH of 4.0, the shrinkage temperature (Ts) of crust leather could reach 79.8°C. In this situation, the SCT tanning agent and aluminum salt tanning agent cross-linked with the collagen. After the combination of SCT tanning agent and aluminum salt, the tensile strength of the leather reached 26.27MPa, the tear strength was 37.52N/mm, and the elongation at break was 70.07%, which was obviously better than that of the leather tanned with SCT alone. Moreover, the leathers tanned with SCT and aluminum salts showed good elution resistance to different chemical media, avoiding the fading defects caused when using aluminum tanning alone.